A goal in packaging integrated circuits is to reduce the cost and difficulty of manufacturing reliable packages. This goal is particularly present in packaging erasable programmable read-only memory devices ("EPROM"), charge coupled devices ("CCD"), and the like. Each such device requires a transparent package surface above the die, such as a quartz window, which increases manufacturing cost and difficulty.
A conventional package for an EPROM device, for example, has a ceramic base and an opposing ceramic lid. The base and/or lid have central depressions. When the base and lid are opposed, the depression(s) define a cavity for the die. The ceramic portions of the base and lid form the sides of the package. The lid has an aperture into which a glass or quartz window is fitted. A conductive metal lead frame is sandwiched between the base and lid. The leads of the lead frame perforate the sides of the package, extending laterally into and away from the cavity. Inside the cavity, the leads are connected to the die by bond wires. Thin layers of frit seal glass bond the base and lid to the lead frame and thus to each other.
Such packages have cost disadvantages, such as the need for a two-piece lid and a lead frame permeating the sides of the package. These and other cost and manufacturability disadvantages are also present in other EPROM packages, such as those shown in U.S. Pat. Nos. 5,043,004 and 5,192,681.